[HttpKernel] RouterListener doesn´t update the context if request is modified

| Q                   | A
| -------------------- | ---
| Bug fix?         | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations?| no
| Tests pass?   | yes
| Fixed tickets  | #8474
| License          | MIT
| Doc PR          | 

This Pull request reverts the patch ea633f5 as discussed in the ticket #8474, and adds a test to prevent regressions.